Spark plasma sintering compaction of hybrid nanodiamond/carbon nanotubes/metal electrode and its application

Nanodiamond has varies of mechanical, chemical and biomedical advantages, but its nano-size and discrete particle properties hinder its wide applications. In this work, we have fabricated a nanodiamond electrode by spark plasma sintering technology and applied it as a heavy metal detection sensor. The detonation nanodiamond was pressed by using spark plasma sintering compaction at 900 K under 0.2 GPa pressure. Then, its structure and composition were analyzed by many characteristic techniques, while the porous electrode having a density of 1.45 g/cm3 with hardness >0.17 GPa. Comparing with traditional carbon-based electrodes, the spark plasma sintering nanodiamond electrode is inexpensive and environment friendly. The analytical performance was characterized and optimized to be 1.52–2.82 μA·μg·L−1 for vary types of heavy metal ions in acetate buffering solution. Ultimately, with stable, accurate and precise electrochemical spectroscopy, this nanodiamond sensor permits rapid detection of Cd2+, Ni2+, Mn2+, Co2+ as well as Pb2+, and could potentially be coupled with point-of-use portable measurement equipment in order to substitute the noble electrodes.